couchdb.bat: change to erlang dir failed if user profile is on a different drive (patch contained)

In couchdb.bat the first thing done is to change to the erlang directory

------ couchdb.bat line 14 - 15 ----------
setlocal
rem First change to the erlang bin directory
cd %~dp0
----------------------------

this failed if the batch file is called by "start menu" and the start menu is on a different drive than the couchdb erlang dir.
-----------------------------
e:\home\mot>"d:\Program Files\CouchDB\bin\couchdb.bat"
CouchDB 0.10.0 - prepare to relax...
'erl.exe' is not recognized as an internal or external command,
operable program or batch file.
-----------------------------

To fix this include "%~d0" after "setlocal"

------ couchdb.bat line 14 - 15 ----------
setlocal
rem First change to the erlang bin directory
%~d0 <<<< new - will change the drive
cd %~dp0
----------------------------